This invention has particular application to general purpose bi-metallic disc temperature controls, sometimes called "snap action" temperature controls, but its application is not limited to them.
In conventional small sized bi-metal disc type snap switches, a bumper or actuator operatively connects the disc with a moveable contact arm. In order to guide the bumper, a third piece is sometimes added between the case that houses the various parts and a closure for the case. In others, a bumper guide is molded in the case but the case is left open at both ends so that the switch can be assembled from an end opposite the disc and disc closure. This requires another cover to complete the enclosure. A generally rectangular flat plate is sometimes used as an actuator, riding in guides in the case, but there is a risk of its binding or jamming. A flat plate circular in elevation has also been used, but it tends to cock or tilt, which causes it to "grow", i.e. to increase its effective length between the disc and the switch arm.
One of the objects of this invention is to provide a thermal switch that can be assembled from one end, is simple and inexpensive.
Another object of this invention is to provide such a switch with an actuator that moves smoothly, with little likelihood of wedging, in guides provided, and with minimal effect on gauging as compared with devices known heretofore.
Another object of this invention is to provide a positive means of locating the snap acting disc and keeping it in proper position both during assembly and in use.
Another object of this invention is to provide, in a stud-mounted thermostat, a stud that permits fabrication of the disc closure on a single automatic machine.
Yet another object of this invention is to provide a construction of terminals to fit a variety of standard connectors.
Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.